1. Field of the Invention
The instant invention relates to an assembly for testing the rolling contact fatigue of a test material. The test material is of the type for manufacturing bearings or other parts subject to rolling contact with adjoining parts. In order to determine which of several materials is best suited for a particular use as, for example, a roller bearing in a specific assembly, a sample test material is subjected to rolling contact at a known pressure or force within a test instrument. The rolling contact fatigue life is determined from the initiation of the test to the time the test material fails, i.e., until the time the test instrument indicates that the test material has succumbed to fatigue. Several materials may be tested and the fatigue lives compared to determine which material is best suited for a particular use.
2. Description of the Prior Art
Full scale bearing tests constitute the ultimate proof of a bearing material, but these tests are expensive and time-consuming. A more effective and expedient way to study a large number of bearing materials is to use a bench tester for subjecting a test material of simple geometry to rolling contact fatigue. A primary goal in bench testing for rolling contact fatigue is to obtain data which is consistent and reliable. A second goal is to limit the complexity of the test instrument. Finally, it is crucial that the test material fail under the test conditions before the test instrument succumbs to the rolling contact fatigue.
The prior art rolling contact fatigue bench test instruments have been limited in their ability to fully and efficiently meet the above-mentioned goals. Prior art instruments sometimes produce results which are inconsistent between runs of several samples. The design of the test instrument is also quite complex. Often the instrument fails before the test material, resulting in vibrations which are falsely indicative of fatigue in the test material.
The instant invention provides a test instrument for obtaining more consistent data. It is simple in concept and design, and it includes means for ensuring that the test material fails in rolling contact fatigue before the test instrument.